Predischarge ST Segment and T Wave Patterns in Predicting Left Ventricular Function and Myocardial Viability in Q Wave Anterior Myocardial Infarction Patients

The aim of this study was to investigate the correlation between ECG changes prior to discharge and findings of early low dose dobutamine stress echocardiography (LDSE) performed in 6 ± 2 days, in patients experiencing their first acute anterior MI. A total of 62 patients admitted with their first acute anterior MI were divided into three groups according to the findings of electrocardiograms performed on the 7-10th days: group A, isoelectric ST and negative or positive T wave; group B, ST elevation (> 0.1 mV) and negative T wave; and group C, ST elevation and positive T wave. There were no significant differences between the groups with respect to thrombolytic therapy and reperfusion criteria. In addition, 90% of the patients in group A (20/22), 66% in group B (12/18, P < 0.05 versus group A), and only 54% in group C (12/22, P < 0.01 versus group A) responded to LDSE. The infarct zone wall motion score index (WMSI) measured by LDSE was significantly decreased in group A compared to basal values (from 2.71 ± 0.65 to 2.07 ± 0.71 P = 0.02), and it was significantly different compared to groups B and C. Moreover, the serum creatinine kinase level of the patients in group C was higher (P < 0.01 versus group A), whereas the ejection fraction was inferior (group A 48%, group B 47%, and group C 41%, P = 0.04 versus group A). When the correlations between good left ventricular function and terminal QRS distortion, sum ST elevation, the number of leads with ST elevation, ST elevation shape on admission, and ST and T alterations in ECG at discharge were investigated, an independent correlation was found between ST and T alteration in ECG and a WMSI value < 2 at rest or after LDSE (P = 0.03, OR 3.08, 95%CI 1.05-8.98). At the infarct zone of patients with ST elevation and positive T waves, left ventricular function is worse and the viability is less. This simple classification may be useful in predicting left ventricular function at the time of discharge.